How Are Brain Tumors Usually Treated?

This article takes a look at the many options for cancer and brain tumor treatment including surgery, radiation therapy, chemotheropy, and other drugs treatments.

Surgery

Treatment of brain or spinal cord tumors usually begins with some sort of surgery, also called resection, to remove all or part of the tumor. Removal of only a small amount of the tumor, known as a biopsy, generally is done when the tumor is inoperable or when surgery must be delayed for some reason. A biopsy can also be helpful if other types of treatment are less risky than resection. Some types of tumors, including diffuse pontine tumors and optic gliomas, are usually not biopsied and treated after a diagnosis by MRI because of the possible risks involved to the child. Although complete removal of the tumor (gross total resection) is often the treatment of choice, partial removal of the tumor will occasionally relieve a child’s symptoms.

Modern surgical equipment and experience allows neurosurgeons to locate and remove tumors previously considered inaccessible. Advanced equipment also helps identify (and therefore avoid damage to) critical areas like cranial nerves or parts of the brain that control speech. Operating microscopes with magnification and illumination allow surgeons to see structures in great detail, frameless stereotaxy provides a road map to structures in the operating room, and ultrasonic aspirators allow tumors to be separated from normal brain or spinal cord.

Surprisingly, brain surgery is not particularly painful, as the brain itself has no pain sensation. It usually involves general anesthesia, causing the patient to be completely asleep for the operation. The head is held in a stable position and the scalp is injected with local painkillers. The scalp is opened and the skull bone is exposed. A trapdoor of bone is created and temporarily removed. The lining of the brain (dura mater) is opened and the brain or tumor is exposed. Once the tumor is removed, the dura mater is sutured closed, the bone is repositioned with titanium plates and screws, absorbable plates and screws, sutures, or fine wire. The scalp is then closed with sutures or staples.

Removal of the tumor often relieves some of the uncomfortable, dangerous pressure that an unwelcome mass in the brain or spinal cord causes. Surgery also establishes the diagnosis by obtaining portions of the tumor for the pathologists to examine. Pathologists can perform a frozen section at the time of surgery to help the surgeon determine the best course of action in the operating room. The frozen section provides only preliminary results, as there are often many special stains and techniques that the pathologist will use to identify the tumor. Some tumor types, including astrocytoma and other gliomas, may be assigned a grade (high or low) that is based on its rate of growth and ability to spread.

After surgery, the patient will usually have a follow-up MRI scan done within the first 2 days. This will confirm the extent of tumor removal and provide a baseline image for future comparison. On occasion, the surgeon, on the basis of the MRI scan findings, may want to return to the operating room to remove a portion of tumor that was not clearly seen at the time of the first surgery.

In some circumstances, resection alone may be curative. Other tumors may require additional therapy such as chemotherapy or radiation therapy.

Some tumor locations may cause a buildup of CSF. In these cases, the surgeon may place a ventriculostomy tube from the spaces of the brain to a drainage bag at the bedside. This allows the fluid pressure to be released while the brain swelling improves. These tubes cannot remain in place forever, because the surrounding tissues are prone to infection. Over the course of a week or so, the ventriculostomy tube drainage is “weaned” so the tube can be removed at the bedside. In a significant percentage of cases, however, a permanent device—called a ventriculoperitoneal shunt (VP shunt)—must be placed to allow internal sterile drainage from the brain to the abdomen for the body to absorb the CSF. In certain circumstances, a third ventriculostomy is performed, in which a small connection is made between where the body makes CSF and where CSF is reabsorbed into the blood. This connection short-circuits the blockage.

Radiation Therapy

Radiation therapy involves aiming beams of X rays or gamma rays at the tumor in exactly prescribed doses over a scheduled period of time. The rays kills the tumor cells by destroying their ability to divide and thus multiply. But radiation therapy, like surgery and chemotherapy, is a double-edged sword. It can harm normal tissue near the tumor, or along the path of the beam traveling in and out of the body to target the tumor, as well as cells of the immune system. The side effects can include brain swelling, fatigue, hair loss, skin irritation, nausea, and vomiting. Newer radiotherapies include intensity-modulated radiation therapy (IMRT)and proton-beam as well as stereotactic (precisely focused), conformal (regionally focused), and hyperfractionated (split-dosing) techniques. CT and MRI scans can be combined in computerized treatment planning. The goal is to provide the maximum dose of radiation to the tumor cells while sparing all healthy cells and tissues around the tumor from harm.

Children must remain absolutely still during these treatments. Because babies and young children may be unable to cooperate, conscious sedation or general anesthesia can be given. Doctors hesitate to treat young children’s brains with radiation therapy. Although it may be effective against the tumor, it can cause significant long-term side effects such as learning, developmental, and memory problems. Your child’s doctor will discuss with you the risks, benefits, and alternatives to help you decide whether radiation therapy should be part of the treatment for your child.

When stereotactic radiosurgery is used, the patient’s head is stabilized in a metal ring and a single dose of radiation is administered from a modified linear accelerator machine, Gamma Knife, or X-Knife. Stereotactic radiosurgery is usually not an alternative to conventional radiation therapy, though it may be recommended as a supplemental treatment. It is an alternative only in rare situations. This technique delivers a highly concentrated radiation dose with little injury to the adjacent brain tissue. Unfortunately, it is not useful for patients with tumors that infiltrate the brain or tumors that are larger than a walnut.

Although most radiation therapy targets malignant tumors, doctors also may use radiation therapy on certain benign tumors that are surgically inaccessible.

Chemotherapy

Chemotherapy is the use of certain chemicals to slow down or kill rapidly dividing tumor cells. Chemotherapeutic drugs are used before, during, or after surgery and radiation therapy. Like radiation therapy, they can also kill beneficial cells and have side effects such as nausea, vomiting, fatigue, infection, bleeding, and hair loss.

Chemotherapeutic drugs include many different medicines. They are used alone or in combination, depending on the type of tumor being treated. Some side effects are unique to certain drugs, such as nerve injury with vincristine, and hearing loss with cisplatin. Doctors carefully monitor the administration of these drugs to minimize side effects, and researchers are continually developing new drugs with improved effectiveness and reduced harmfulness.

Although some chemotherapeutic drugs can be taken orally, most are given intravenously through a vein in the arm or hand. When chemotherapy is going to take place over an extended period of time or will be given to a child whose veins are small or hard to access, doctors may suggest surgically implanting a device in a major vein, giving easy access to a vein without repeated needle sticks. Once implanted, the device can be used not only for chemotherapy but also for antibiotics, fluids, blood transfusions, and for drawing blood for laboratory work.

Currently there are two devices commonly used for long-term access to the veins. Both are catheters inserted under the skin. The insertion is a minor surgical procedure that may require an overnight hospital stay or may be done as outpatient surgery. One end of the catheter is threaded into a large vein in the chest. The other end, into which the IV drugs will go, can either exit the chest through the skin (as with the Broviac or Hickman) or be left just under the skin (as with the Port-a-Cath), terminating in a little rubber reservoir into which the drugs are injected with a needle. A skin-numbing cream (EMLA) can be used over the reservoir to relieve the pain of a needle stick before the Port-a-Cath or Mediport is accessed.

If your child’s doctor recommends a catheter, be sure to discuss with him or her the benefits and risks of each type. The Broviac requires some special care at home; medical personnel will teach you what you need to know.

You can obtain more information about the short- and long-term effects of these therapies from your treatment center and the many resources listed in the Web site area tited “Resources”. Medications are available to relieve some of the uncomfortable immediate and short-term side effects. Long-term side effects may require follow-up care by other specialists. Consult your child’s doctors about your child’s specific needs and before treating any related health-problem on your own—even skin irritation.

Additional Treatments and Drugs

Excess fluid in the brain causes a variety of problems in brain tumor patients. As you have read, hydrocephalus results from excess CSF in the brain and leads to a variety of unpleasant symptoms. To relieve the buildup of CSF, doctors may surgically implant a flexible piece of narrow tubing into the brain and thread the other end of the tubing under the skin either into the abdominal cavity or through a vein to the heart. The CSF can then flow down the shunt, as it is called, away from the brain, and be absorbed into the body or filtered through the blood stream. Sometimes another CSF pathway can be established by a newer procedure called a third ventriculostomy. This procedure may avoid the need for a shunt.

If your child needs to have a shunt implanted, you will need to know the type of shunt, possible problems, and what symptoms to be aware of that represent a possible problem. More information on shunts can be obtained from the Hydrocephalus Association.

Some tumors cause the normal brain tissue around them to swell with excess fluid and inflammation. Surgery and radiation therapy can also produce swelling. Whatever the cause of the swelling, doctors routinely prescribe Decadron (dexamethasone), a steroid and anti-inflammatory drug that reduces swelling. This treatment usually brings dramatic relief to the child who has been having headaches, vomiting, and nausea due to swelling.

Steroids are powerful, wonderful medicines, but they may have side effects: increased appetite, high blood pressure, susceptibility to infection, facial swelling, acne, and fluid retention. Children may have an artificial cheerfulness (euphoria) and experience an emotional letdown or mood swings as the dose is decreased. Children taking Decadron may have an enormous appetite! It is very important to take these medications with food to avoid stomach irritation or bleeding. Antacids may be prescribed to help protect the stomach. The body’s response to taking steroids is to stop its own production of steroids, so it’s important that patients not discontinue this medicine abruptly. When the doctor wants the drug stopped, the dosage will be gradually tapered off.

Children undergoing chemotherapy or radiation therapy may face the discomfort of nausea and vomiting. There are drugs available to alleviate these symptoms called antiemetics. If you see your child developing nausea, speak with your child’s medical team. There are different medications available, so you will be able to work with your child’s doctors to find the best antinausea treatment for your child.